rtlib: FileFlush device driver calls

- no need to check for FB_FILE_TYPE_NORMAL, if device has pfnFlush function ptr set, then it's OK to call
- besides, OPEN "CON" is FB_FILE_TYPE_CONSOLE, and calling pfnFlush is OK
- FB_UNLOCK() must be after the call to pfnFlush, so fb_FileFlush retains locks until after fflush() call

src/rtlib/file_flush.c

@@ -7,6 +7,8 @@ FBCALL int fb_FileFlush( int fnum )
 {
 FB_FILE *handle;
 
+    int res;
+
     FB_LOCK();
     handle = FB_FILE_TO_HANDLE(fnum);
 
@@ -16,12 +18,6 @@ FB_FILE *handle;
         return fb_ErrorSetNum( FB_RTERROR_ILLEGALFUNCTIONCALL );
     }
 
-    if (handle->type != FB_FILE_TYPE_NORMAL)
-    {
-        FB_UNLOCK();
-        return fb_ErrorSetNum( FB_RTERROR_ILLEGALFUNCTIONCALL );
-    }
-
     if (handle->access == FB_FILE_ACCESS_READ)
     {
         FB_UNLOCK();
@@ -30,12 +26,15 @@ FB_FILE *handle;
 
     if( handle->hooks && handle->hooks->pfnFlush )
     {
-        FB_UNLOCK();
-        return handle->hooks->pfnFlush( handle );
+        res = handle->hooks->pfnFlush( handle );
     }
     else
     {
-        FB_UNLOCK();
-        return fb_ErrorSetNum( FB_RTERROR_ILLEGALFUNCTIONCALL );
+        res = fb_ErrorSetNum( FB_RTERROR_ILLEGALFUNCTIONCALL );
     }  
+
+    FB_UNLOCK();
+
+    return res;
+
 }